IMPACTS OF CLIMATE CHANGE ON SORGHUM (Sorghum bicolor (L.) Moench) PRODUCTION UNDER VARIOUS MANAGEMENT PRACTICES IN HARAMAYA DISTRICT, EASTERN ETHIOPIA

Abstract

Systematic analysis of climate change and variability at local scale is critical to improve planning on agricultural activities and thus reduce vulnerability of the community. Therefore, the present study was aimed to analyze trends of climate variables and assessing its potential effects on sorghum production in the Haramaya District. Historical climate data (1985-2016) were collected from National Meteorological Agency of Ethiopia. Future climate data (2020-2099) were downscaled from complete ensemble of General Circulation Models for Representative Concentration Path Ways (RCPs) of 4.5 and 8.5 using MarkSim Weather Generator tool. Crop and soil data were acquired from Haramaya University Sorghum Research Program and existing source, respectively. INSTAT +3.036 and XLSTAT were used to analyze rainfall and temperature data. Decision Support System for Agro-technology Transfer was used to assess the impact of climate change on sorghum yield. The result of historical climate data showed an increasing trend for annual and seasonal rainfall except for belg season. Similarly, both maximum and minimum temperature showed increasing trend. The increasing trend was significant for maximum temperature whereas, minimum temperature showed significant trend only during kiremt season. Likewise, future annual and seasonal rainfall totals exhibit increasing trend under all considered scenarios except slight decrease in belg rainfall. Moreover, mean annual, seasonal and monthly temperature is projected to increase under both emission scenarios. The impact of climate change on sorghum yield was inconsistent. The result showed that there would be a general increase in grain yield of sorghum under RCP 4.5 whilst reduction in grain yield is projected under RCP 8.5, particularly, in the late century. Planting window of late May and early June found to be the best planting dates. Evaluated plant population and row spacing play positive role for sorghum yield in the future climate. Averaged for all scenario, an application of 150kg/ha of nitrogen fertilizer would increase sorghum yield in the future.